in pcl ch3, the author demonstrates using cl instead of sql for database
afaik hn doesn't use sql/rdbms either, i guess it's because threaded forum is better suited using a tree-like data structure instead of simple table
i stopped using sql (after reading pcl and seeing the fact of hn) and just having a lisp process running, writing to disk every 5 mins
i'm now experimenting with nginx's proxy_pass and upstream to many lisp unix sockets (weighted round robin)
virgin territory for me, it's quite fun so far ... foolish and hungry :D